In our earlier U.S. patent application Ser. No. 13/970,100, and which was filed on Aug. 19, 2013, we described an orthodontic bracket which when used in combination with an arch wire provides first, second, and third orders of movement of the patient's tooth without a clinically predetermined manipulation of the arch wire which is received in the transversely disposed arch wire slot. The various forms of the invention as disclosed in this pending US patent application provides a multitude of patient and clinical advantages not possible in orthodontic appliances which have been utilized heretofore. The teachings of this prior co-pending patent application are incorporated by reference herein.
Generally speaking, first order movements are commonly thought of as tooth rotation, and in/out tooth control. Further, second order movements are often referred to as “tipping” the root in a mesial and/or distal angulation or elevation, and/or depression of a tooth position. Further, third order movement, or “couples,” have resulted in the expression of “torque” which causes the axial inclination of a tooth from a flared or uprighted orientation to its final and desired position.
From its earliest utilization, and to achieve ideal tooth positioning, a clinician has, heretofore, been required to bend round and rectangular shaped arch wires to express the in/out, up/down, tipping, and torque to accomplish a final, desired tooth position. This activity not only took long periods of time, and advanced clinical practice skills, but it was nearly impossible for most clinicians to control the resulting treatment forces applied in all planes of space. As a result, treatment times for patients were often unduly long in duration, and the resulting treatment forces which were applied often had a negative long term impact on the patient's bone and tissue.
In 1970, Dr. Larry Andrews invented what was later termed a “straight wire” appliance. This bracket design allowed significant improvements to first and second order movements, and lessened the need for the predetermined bending of the arch wires. However, this design still lacked adequate third order control of tooth axial inclination. The term “straight wire orthodontics” misled many clinicians to believe that only one bracket torque prescription on each anterior tooth was adequate to express a final desired tooth position. Unfortunately, without bending rectangular arch wires to individualize finishing torque on individual teeth, this had nearly the same effect as treating patients using only round wires in the bracket arch wire slot. This, of course, negated any third order control. For example, if a 0.019 inch×0.025 inch stainless steel rectangular working or finishing arch wire is placed in a 0.022 inch arch wire slot, there is approximately 11 to 12 degrees of play, or freedom of movement, in either direction, for a total of 22 to 24 degrees of play or movement before a third order “torquing couple” is achieved between two opposite corners of the rectangular shaped arch wire, and the opposing walls of the bracket arch wire slot. Over the years, some clinicians have tried to fill the arch wire slot with larger cross-sectional rectangular arch wires to achieve third order control, but many have found it difficult to finally position teeth due to the binding, and friction which is experienced in the arch wire-bracket interface. The use of these larger dimensioned finishing rectangular arch wires in most clinical settings resulted in the application of unfavorable physical forces, in both magnitude, and direction which made final tooth positioning far more challenging for the clinician. This also resulted in potentially negative, long term impact on the patient's bone and tissue. For this reason, most clinicians have tried to bend the appropriate amount of torquing couple into the smaller dimensioned rectangular arch wires so as to correctly procline or upright the axial inclination of the teeth to their final desired position. It should be readily apparent that the multitude of variations which may impact the third order tooth movements are many, and consequently, orthodontists typically are not readily able, in most clinical settings, to rapidly, and accurately calculate the amount of third order couple that is needed, and the appropriate amount of force that should be applied to a given tooth to achieve the desired amount of tooth movement. Consequently, because of clinician miscalculation, treatment times for any given patient are often extended as individual clinician's strive to achieve the desired tooth position, and alignment which is appropriate. Additionally, it will be recognized that this miscalculation of the appropriate amount of force to express third order torque may result in excessive discomfort to the patient, and as previously mentioned, potentially negative long term potential health issues may arise for the orthodontically treated patient.
While the numerous advantages to be achieved by utilizing the various forms of the orthodontic bracket as seen in our earlier filed application Ser. No. 13/745,638 are many, an ongoing need remains for the development of an orthodontic bracket which is readily and easily utilized by the clinician, in a clinical setting, and which further provides a rapid means for adjusting the orthodontic bracket in order to achieve assorted first, second and third order movements of a patient's tooth in a manner not possible heretofore. A new orthodontic bracket which achieves these objectives is the subject matter of the present application.